Submarines have been valued by countries all over the world for their unique concealment and strong combat effectiveness. Due to the significant role of submarines, submarine technology advances by leaps and bounds.
Currently, with respect to submarine technology development in the world: the US Ohio-class nuclear submarine has a length of 170.7 meters, a width of 12.1 meters, a displacement of 18,750 tons, a maximum dive depth of 400 meters, and a ship speed of 20 knots; the US most advanced Virginia-class nuclear submarine has a length of 115 meters, a width of 10 meters, a displacement of 8,000 tons, a maximum dive depth of 500 meters, and a ship speed of 25 knots; the Russian Borey-class nuclear submarine has a length of 170 meters, a width of 13 meters, a maximum dive depth of 450 meters, a displacement of 17,000 tons, and a ship speed of 26 knots; the UK vanguard-class nuclear submarine has a length of 149.9 meters, a width of 12.8 meters, a maximum dive depth of 350 meters, a displacement of 16,000 tons, and a ship speed of 25 knots; the French Triomphant-class nuclear submarine has a length of 138 meters, a width of 12.5 meters, a displacement of 14,000 tons, a maximum dive depth of 500 meters, and a ship speed of 25 knots; China's Type 095 nuclear submarine has a length of 150 meters, a width of 20 meters, a displacement of 15,000 tons, a maximum dive depth of 600 meters, and a ship speed of 35 knots; India's Chakra nuclear submarine has a length of 115 meters, a width of 14 meters, a displacement of 9500 tons, a maximum dive depth of 650 meters, and a ship speed of 32 knots; Germany's Type 214 submarine has a length of 65 meters, a width of 6.3 meters, a displacement of 1,700 tons, a maximum dive depth of 400 meters, and a ship speed of 20 knots; and Japan's Soryu-class nuclear submarine has a length of 84 meters, a width of 9.1 meters, a displacement of 4,200 tons, a maximum dive depth of 500 meters, and a ship speed of 20 knots.
Deep diving submersibles are diving devices that can work underwater in the deep sea. They generally have a displacement of about 20-80 tons (though in individual cases reaching about 300-400 tons), a diving depth generally of about 2,000-5,000 meters (though in individual cases reaching about 11,000 meters), and are mainly used for marine survey, exploration, detection, mine-laying, rescue of submariners of a disabled submarine. Japan's “Deep Sea-6500” submersible can seat 3 passengers and operates to a water depth of 6,500 meters; China's “Jiaolong” manned submersible dives to 7,062 meters; Russia's Mir 2 manned submersible is of the class of 6,000 meters; the director Cameron of “Avatar” drove the “Deep Sea Challenger” manned submersible to dive into the deep water of 10,898 meters in the Mariana Trench; and the US “Trieste” deep submersible has a maximum manned diving depth of 10,916 meters, which is only 118 meters less than the deepest point of the ocean, the Mariana Trench, which is 11,034 meters deep.
Submarine sea damage accidents in peacetime often occur. These accidents can be caused by collision, stranding, sea waterline damages, striking a rock, fire disasters, explosions, operational errors, sea-conditions, rudder sticking, technical and device failures, and the like. During 90 years between 1900 and 1989, worldwide non-combat sea damage accidents of submarines totaled 631 cases, and caused 287 submarines to be wrecked and sunk. Among these accidents, 75% of the wrecked submarines were at a depth where a submariner “could escape”, and 85% of the wrecked and sunk submarines were settled on the seabed at a certain depth or suspended at a certain depth where the submarines could not be floated by themselves. In the latter case, the submariner could use the self-rescue device provided inside the submarine to self-rescue and escape or could be rescued by means of a rescue device.
Currently, the facilities used for escape (self-rescue) of a submariner from a wrecked submarine include the following: a collective floating rescue capsule, a fast-rising danger escape device, and an underwater danger escape device; and the equipment for underwater life-saving (rescue includes: a deep diving lifeboat, a rescue bell system and a submarine rescue ship.
The submarine rescue ship's task includes carrying submarine rescue personnel, the diving rescue bell system, a deep-diving lifeboat system and support equipment, other submarine rescue instruments, etc., to the sea area where the submarine was wrecked to carry out the rescue.
The deep-diving lifeboat refers to a miniature dinghy that can dive into the deep sea to rescue a submariner from a wrecked submarine and has a basic structure similar to that of a submarine. The lifeboat has a displacement of over ten tons to dozens of tons, and a ship speed of several knots. The lifeboat has a small endurance, and thus is generally carried by a deep-diving life-saving mother ship or a salvage lifting vessel to the sea area where the submarine is wrecked. The under-boat cylindrical connection device is docked with a rescue platform of the wrecked submarine to form a passage, so as to rescue the personnel of the wrecked submarine into the deep-diving lifeboat and then transfer them to the mother ship. Deep-diving lifeboats generally have a diving depth of 600-1,000 meters, though the deep-diving lifeboat with the maximum rescue depth is the US DSRV, with a maximum diving depth of 1,524 meters.
Japan's “Chiyoda”, which was commissioned in 2018, is a 5,600-ton-class submarine rescue ship with a length of 128 meters, a maximum deck width of 20 meters, and a maximum ship speed of 20 knots. It uses a deep-sea diving device carried on it to rescue the submariner.
The above-mentioned self-rescue and rescue facilities are all utilized to rescue the submariner of the wrecked submarine.
However, submarine rescue technology develops slowly. The self-rescue and rescue technology for submarine rescue still has many technical problems that are difficult to solve. Submarine rescue technology does not develop at the same pace with submarine technology and thus there is a great difference between submarine technology and submarine rescue technology.
The prior art launches a deep-diving rescue bell, a deep-diving lifeboat, and the like, towards the submarine, docking them with the rescue platform of the submarine to form a rescue passage, so as to rescue the submarine personnel into the deep-diving lifeboat and then transfer the personnel to the mother ship, which requires that the deep-diving rescue device be docked with the submarine in the deep sea. Since the water pressure in the deep sea is very high, sometimes the precise internal conditions of the submarine are unknown, and the technical difficulty is great. The maximum rescue depth of the current deep-diving rescue methods is about 1,524 meters which can only be achieved by the United States. However, this rescue method can only rescue people (not submarines) and has a low speed; these are significant limitations which serve as an example of how submarine rescue technology is at a significantly different level from the level of deep diving submersibles by which humans conquer the deep sea.